As the newest standard with general versatility for connecting a plurality of digital household electric appliances, the HDMI standard has been defined. In the HDMI standard, CEC (Consumer Electronics Control) protocol is used. By using the CEC protocol, coordination of the devices connected by the HDMI cables is designed.
TABLE 1CEC COMMANDSCOMMON CODEImage View OnActive SourceUser Control PressedRecord OnRecord OffStandBySet Stream PathSTANDARD ERROR MESSAGEVENDER UNIQUE CODEMENU SETTING TRANSFERPROGRAM INFORMATIONSPECIAL REMOTE CONTROL KEYDETAILED ERROR NOTIFICATION
Table 1 shows examples of CEC commands, and the CEC commands are broadly divided into a common code which is provided for keeping general versatility and is common without depending on each appliance or a vender, and a unique code unique to a vender for allowing the degree of freedom, which the vender can uniquely define.
For example, a coordination system for allowing a device to have a function by using a vender unique code (command) of the HDMI has been announced.